1. Field of the Invention
The invention relates to a heat transfer monitoring and/or measuring device, especially a flow indicator and/or a flowmeter for flowing media, with a preferably flexible component carrier, preferably with electrical and/or electronic components, with a heating element, with at least one temperature measuring element, with an electrical connection possibility and with a housing. In particular, to such a device in which the electrical and/or electronic components are located on the component carrier and are connected to one another to form a circuit and in which the heating element and the temperature measuring element are made pin-shaped.
2. Description of Related Art
It was stated initially that the invention relates to a heat transfer monitoring and/or heat measuring device. Here, heat transfer monitoring device stands for a device in which heat transfer is simply monitored, in which therefore only the presence or absence of a certain heat transfer is ascertained. Conversely, heat transfer measuring device stands for a device in which heat transfer is measured; therefore, an analog measured value which corresponds to the heat transfer is obtained which can also be converted into a digitized measured value. In other words, a heat transfer monitoring device delivers a qualitative statement "heat transfer present" or "heat transfer absent", while a heat transfer measuring device makes a quantitative statement about heat transfer.
Heat transfer monitoring devices or heat transfer measuring devices of the type under discussion here are used especially to record heat transport by flowing media. They are then flow indicators or flowmeters, in the sense of the aforementioned differentiation, a flow indicator corresponding to the heat transfer monitoring device and a flowmeter to a heat transfer measuring device.
Generic heat transfer monitoring devices or heat transfer measuring devices as well as flow indicators or flowmeters work according to the calorimetric principle. Generally, differential temperature measurement is used. A first temperature measuring element measures the actual measured temperature, the measured temperature resulting from the heat output of the heating element, the temperature of the flowing medium and the heat transport capacity of the flow medium which depends on the flow. Furthermore, generally, a second temperature measuring element measures a reference temperature; but, measurement of a reference temperature is not absolutely essential, and can be omitted if, for example, the temperature of the flowing medium is known.
In the prior art heat transfer monitoring and/or measuring devices which operate according to the calorimetric principle, especially flow indicators and/or flowmeters, various embodiments are known (compare German patent document nos 24 47 617; 26 29 051; 32 13 902; 37 13 981; 38 11 728; 38 25 059; 39 11 008; and 39 43 437). In particular, heat transfer monitoring and/or measuring devices of the initially mentioned type are known which have a flexible, more or less film-like component carrier and electrical and/or electronic components, the electrical and/or electronic components being located on the component carrier and being connected to one another to form a circuit.
It is common to all heat transfer monitoring and/or measuring devices of the type to which the invention is directed that:
a) they can only be produced relatively expensively; in particular mounting is expensive; PA1 b) they are generally at least partially potted, therefore at least partially filled with a casting resin; PA1 c) especially due to b), they essentially cannot be opened, and PA1 d) due to b) and c), they cannot be repaired in case of a defect and the parts not affected by the defect cannot be re-used.